# OSTConf vs Gas Blender Toolkit

The clearest difference is price: OSTConf at Free against Gas Blender Toolkit's $2.99. Gas Blender Toolkit's advantage is review sentiment (60% vs 25%) and update cadence (every 9 days vs every 5 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

OSTConf is free to download; Gas Blender Toolkit costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

OSTConf ships an update every 5 months, Gas Blender Toolkit every 9 days. The most recent releases landed on November 2, 2026 and November 11, 2026 respectively.

## The numbers

| Metric | OSTConf | Gas Blender Toolkit |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | — | **[3.0 (2 ratings)](https://appshunter.io/ios/app/gas-blender-toolkit/id1467768490/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | 25.0% of reviews | **60.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 9 days** |
| Monetization | **Free** | Paid |
| Best chart rank | — | **#105** |
| Size | 3 MB | 3 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kai-Uwe Sattler](https://appshunter.io/developer/500229044) | [Oleg Gurevich](https://appshunter.io/developer/1467768489) |

## What reviewers say

### OSTConf

[App page](https://appshunter.io/ios/app/ostconf/id1404182943)

Configure your dive computer settings and parameters wirelessly. Update date, time, custom text, gas mixes, and deco settings. Compatible with recent Bluetooth-enabled dive computers.

**Highlights:** Read and modify settings, Update date and time, Set custom text, Configure gas mixes, Set deco parameters, Upgrade firmware, Retrieve device information

**Features:** macOS Compatibility

**In-app purchases:** none


### Gas Blender Toolkit

[App page](https://appshunter.io/ios/app/gas-blender-toolkit/id1467768490)

**Currently charting:** #105 Top Paid · Sports (US App Store)

This comprehensive toolkit assists scuba divers in calculating and blending various gas mixtures like trimix, nitrox, and heliox. It offers features for both partial pressure and continuous blending, cost calculation, and utilizes ideal and real gas models for accuracy. Optimized for larger screens, it serves as a successor to a previous diving application.

**Highlights:** Partial pressure blending, Continuous blending, Trimix, nitrox, heliox calculations, Ideal and real gas models, Cost calculation, Top off from storage

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is OSTConf free?

OSTConf is free to download, with no in-app purchases.

### Is Gas Blender Toolkit free?

Gas Blender Toolkit costs $2.99, with no in-app purchases.

### Do OSTConf or Gas Blender Toolkit have ads?

Neither OSTConf nor Gas Blender Toolkit shows ads.

### Which is updated more often, OSTConf or Gas Blender Toolkit?

OSTConf ships an update every 5 months, and Gas Blender Toolkit every 9 days. Most recently, OSTConf was updated on November 2, 2026 and Gas Blender Toolkit on November 11, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*